/*
 * Mem_manager.c
 * 
 * Copyright (c) 2011-2013 BGI-Shenzhen <soap at genomics dot org dot cn>. 
 *
 * This file is part of SOAPdenovo-Trans.
 *
 * SOAPdenovo-Trans is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * SOAPdenovo-Trans is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with SOAPdenovo-Trans.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "stdinc.h"
#include "newhash.h"
#include "extfunc.h"
#include "extvab.h"

MEM_MANAGER *createMem_manager (int num_items, size_t unit_size)
{
	MEM_MANAGER *mem_Manager = (MEM_MANAGER *) ckalloc (1 * sizeof (MEM_MANAGER));

	mem_Manager->block_list = NULL;
	mem_Manager->items_per_block = num_items;
	mem_Manager->item_size = unit_size;
	mem_Manager->recycle_list = NULL;
	mem_Manager->counter = 0;
	return mem_Manager;
}

void freeMem_manager (MEM_MANAGER * mem_Manager)
{
	BLOCK_START *ite_block, *temp_block;

	if (!mem_Manager)
	{
		return;
	}

	ite_block = mem_Manager->block_list;

	while (ite_block)
	{
		temp_block = ite_block;
		ite_block = ite_block->next;
		free ((void *) temp_block);
	}

	free ((void *) mem_Manager);
}

void *getItem (MEM_MANAGER * mem_Manager)
{
	RECYCLE_MARK *mark;	//this is the type of return value
	BLOCK_START *block;

	if (!mem_Manager)
	{
		return NULL;
	}

	if (mem_Manager->recycle_list)
	{
		mark = mem_Manager->recycle_list;
		mem_Manager->recycle_list = mark->next;
		return mark;
	}

	mem_Manager->counter++;

	if (!mem_Manager->block_list || mem_Manager->index_in_block == mem_Manager->items_per_block)
	{
		//pthread_mutex_lock(&gmutex);
		block = ckalloc (sizeof (BLOCK_START) + mem_Manager->items_per_block * mem_Manager->item_size);
		//mem_Manager->counter += sizeof(BLOCK_START)+mem_Manager->items_per_block*mem_Manager->item_size;
		//pthread_mutex_unlock(&gmutex);
		block->next = mem_Manager->block_list;
		mem_Manager->block_list = block;
		mem_Manager->index_in_block = 1;
		return (RECYCLE_MARK *) ((void *) block + sizeof (BLOCK_START));
	}

	block = mem_Manager->block_list;
	return (RECYCLE_MARK *) ((void *) block + sizeof (BLOCK_START) + mem_Manager->item_size * (mem_Manager->index_in_block++));
}

void returnItem (MEM_MANAGER * mem_Manager, void *item)
{
	RECYCLE_MARK *mark;

	mark = item;
	mark->next = mem_Manager->recycle_list;
	mem_Manager->recycle_list = mark;
}